Pilot adjusting screw on '78 Kz1000?

Hey,

I'm trying to get my 1000 back on the road after too many years of being parked in the garage.

To make a long story short, I bought a set of spare VM26 carbs from eBay to rob parts for my messed up original VM26 set that came on my Kz1000A2.

As far as I can tell the spare carbs came from a '78 Kz1000A2A because they have the 5CN7 needles. I was in the process of picking and choosing the best components to make one good set of carbs when I ran across something.

On the left is the pilot adjusting screw from my original carbs.
On the right is the pilot adjusting screw from the spare carbs.



The screw on the left is blunt and does not look as if it's been broken, sheared, or filed.
The screw on the right is what is shown on all the parts fiche's that I can find.

Any one have a clue to which one I should use? I'm thinking the left as it was native to my stock carbs.

Thanks.

Later, Doug

I have never seen one with a blunt end like that, but then I have not seen all the pilot screws that are out there.

Agree it does not appear to have been broken or filed, at least it does not appear that way in the pictures you posted.

I also notice that the original screw just does not have the same taper that the replacement carbs screw has. Maybe it is just the way they appear in the picture, but that is the way it looks to me. This sort of makes me wonder if the replacement carb's screw would fit the passageway correctly and have the same adjustment ability as the original does. To me it would appear that it could not fill the passage as well as the original one can.

Hope others will chime in with more info on this.

One way to tell what model the carbs came from would be via the ID stamped on the flange just below the choke handle. If I am not mistaken the carbs should have the following IDs
the A2
102
5

the A2A
102
4

www.z1enterprises.com/ItemDetails.aspx?i...77-78&item=KL18-2608

www.z1enterprises.com/ItemDetails.aspx?i...carb&item=SIK-1157SK

Good Fortune!

That is interesting. I wasn't aware that the VM28s had fuel enrichment screws. Always thought only the 26s had those and the 28s had air screws. The long pointed ones are exactly like the ones in my 26s.

Hey Patton, you know a good deal about 29s, or someone that is tits on them? Give me a shout.

The pointed ones are pilot screws, (bottom of carbs), the blunt are air screws, (top of carbs). Not even close to interchangable. 78 Kz1000 should use pilot screws. Pointy.

Easy way to remember which screw does what is, The fuel adj. screw will always be in front of the slide, the air adj. screw will always be behind the slide.
Backing out an air screw adds more air to the circuit. Backing out a fuel screw will add more fuel to a circuit.

I agree, the blunt ones are air screws and the pointed set is for idle fuel enrichment.
Thing is, none of my 1000 carbs, 26s, 28s, or 29s have air screws that look like those in his picture.
Y'all aren't saying Streetfighter doesn't know which orifice to screw those into are ya? :whistle: :evil:

I took the blunt screws out of the passage way that is behind the slide, in the middle, next to the carb mounting flange.

The point screw came from the exact same location on the donor carbs.

I can take pics when I get home if necessary.

I'll also try to get the ID stamp for both carbs when I get home.

Later, Doug

perhaps the PO of replacement carbs used wrong rebuild kit

Yes sir, if your donor carbs had the pointed needles behind the slide/rear of carb, they were in the wrong place.

OldSchoolZ wrote: Yes sir, if your donor carbs had the pointed needles behind the slide/rear of carb, they were in the wrong place.

not wrong place, just the wrong needles.
For the sake of no more confusion in this thread, let's state the rear of the carb as the air filter mounting point, the inlet side, or air filter side.

StreetfighterKz wrote: I took the blunt screws out of the passage way that is behind the slide, in the middle, next to the carb mounting flange.

FWIF, I'm pretty sure by his description what he is talking about, but this statement could cause some confusion with others not so familiar with these carbs. The carb mounting flange, to me, would be the portion that mounts into the intake manifold boots on the cylinder head.

I'm not familiar with what type of needles come in rebuild kits, as I always used factory parts on these carbs in the past.
Is the blunt nosed air screw that he pictured what comes in rebuild kits? Because I've never seen one of that design before now. Just wondering if that is even supposed to be used in the VM carbs??? :huh:

Both of the screws shown in the picture appear to be pilot screws - notice the end a screw driver would interface with it is knurled which is what all of the pilot screws I have seen are like and none of the air screws I have see are like.

According to streetfigher, they both were removed from the pilot screw locations, bottom of carb on engine side of the carb as opposed to the air screw location on the air filter side on the carb. I suppose someone in the past could of installed something different than stock, but I just have never seen any pilot screws with the blunt end like these have other than some that the tip has broken off of.

Something that does not appear to have asked, are all 4 of the screws from the original carbs blunt like the one in the picture? Or is it the only one that way?